I have been using the DNS service included in Router os since 8 years. Principaly, I use this service for local doman “.lan” devices.
Once I updated to RouterOS 7.7 I notice that all containers hosted in an external host (not in RouterOS) can not resolve any local domain. It seems they arrive to query but the answer can not come back to the host. This is happening only with docker containers configured with the network option to “host” while containers configured in “bridge” mode can access without problem. The resolv.conf file of the docker container inherits the nameserver from the host which is the Mikrotik IP (192.168.1.1) so all seems to be OK configured.
So it works for some but not all? Then it means that RouterOS is doing something and it would need a closer look (e.g. catch and examine some packets) to see what’s wrong.
It could be the problem with 7.7 erroneously returning NXDOMAIN for AAAA records (or others, but these are most likely to get queried by clients) if you define only A. That was fixed in 7.8 (currently only RC, but otherwise probably not worse than 7.7).